It's quite easy to cause more damage from cleaning so if you're not comfortable with cleaning your PC yourself, take it to a shop for servicing. Otherwise, you can unplug and disassemble the computer to do it yourself. You'll need a can of compressed air and an anti-static rag to remove stubborn clumps of dust. art - This extension indicates an image file that was compressed with AOL (America Online) technology. Both Internet Explorer and the AOL service software can display this kind of file, however if you don't have AOL installed on your system, Internet Explorer will display it. .avi - This extension indicates a video file playable by most multimedia viewers including Microsoft's Media Player. Children just don't have the experience that adults have and they don't have the skills required to handle inappropriate conversations, emails, or images found online. NOTE: Some of these tools include kid-specific web browsers that will visit pre-approved websites. Others include browser plug-ins that won't allow access to online areas that contain forbidden keywords. Both files are capable of opening plain text, however WordPad can open Windows Write files (an earlier version of WordPad) as well as rich text files. WordPad can also save documents as plain text, rich text, and MS Word documents. So with WordPad having the ability to read and create rich text; embed objects (sound, pictures, and video); and manipulate fonts, we have to wonder if other word processors, which do the same thing, are really necessary. This will decrease the time it takes for your computer to send it elsewhere, and it will also decrease the time it takes for someone else to download it. To create your own .zip or .sit file, you can select a single file or a group of files from within Explorer, and right-click the selection. Again, depending on how you installed Winzip or StuffIt, you can click the "Add to Zip" or "Add to Sit" option and have these programs automatically archive the file(s) into one. Unless the activities on your computer are restricted to pure textual output (plain text files), your computer is going to get filled with a lot of "stuff" - stuff that can overfill a PC's capacity too much for the computer to function well. The problem is that while upgrading a computer is always an option, technology advances so fast that newer products (such as memory chips, new drives, etc.